Field of the Invention
This invention relates to separation or enrichment of isotopes and more particularly refers to a new and improved method of isotope separation or enrichment in a vaporous mixture of compounds of the isotopes by means of coherent, polarized electromagnetic radiation.
2. Description of the Prior Art
Isotope separation or enrichment in a vaporous mixture of compounds or atoms of the isotopes by means of coherent, polarized electromagnetic radiation are known. Such radiation can be obtained by lasers of varied types. At various times, proposals also have been made to use such high-energy radiation for exciting atoms and molecules, specifically as to nuclides, and to perform thereby the separation of isotopes or an enrichment of the isotopes.
In view of the fuel supply for nuclear power plants, the enrichment of the uranium isotope U 235 is especially of great interest, as the heretofore practiced processes for separation of U 235, such as, for example, gas diffusion, are extremely expensive and require a large amount of technology.
Uranium vapor has alredy been proposed as the starting material for the uranium isotope separation or enrichment. However, the execution of these methods, technically, is very difficult because of the requirement of very high temperatures of more than 2000.degree. C. Of the uranium compounds, UF.sub.6 has the highest vapor pressure. For this reason, and because fluorine has no isotopes, it has been proposed to selectively excite and enrich one UF.sub.6 isotope compound by means of laser radiation. Reference is made here particularly to the U.S. Pat. Application Ser. No. 579,544, which relates to the utilization of the molecule dipoles induced by the electric field of the radiation. These dipoles, excited specifically as to the isotopes, are suitable not only for separation by physical means, but they also constitute molecules in an excited state, in which they readily are capable of entering into, for example, chemical reactions with reaction partners or reactants that are supplied to them. It has been found, however, that it is relatively difficult to obtain the desired or necessary high excitation energy, as the rotational vibration frequencies of the molecules with higher excitation stages change as a rule toward lower frequencies and the molecules are therefore no longer able to absorb the exciting, constant-frequency radiation to the original extent. This vibration behavior corresponds to that of an anharmonic oscillator.